This disclosure relates generally to presenting content to users of an online system, and more specifically to presenting content to a group of users of the online system subject to limitations on a number of times certain content is presented within a time interval.
Online systems, such as social networking systems, allow users to connect to and to communicate with other users of the online system. Users may create profiles on an online system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Online systems allow users to easily communicate and to share content with other online system users by providing content to an online system for presentation to other users. Content provided to an online system by a user may be declarative information provided by a user, status updates, check-ins to locations, images, photographs, videos, text data, or any other information a user wishes to share with additional users of the online system. An online system may also generate content for presentation to a user, such as content describing actions taken by other users on the online system.
When selecting content items for presentation to users, many online systems account for ratings or quality scores of content items. Ratings for content items are received from users of the online system may describe a user approval or disapproval of the content included in content items, describe likelihood of users interacting with the content included in content items, describe user assessment of whether content of content items is appropriate or inappropriate, or describe any other user reaction to the content of the content items. Based on ratings received for various content items, an online system may generate or train a model that determines a quality score for content items based on characteristics of content items and ratings received from users for content items having various characteristics.
Many online systems receive ratings for presented content items from a specific group of users. However, a group of users from whom ratings for content items are received often includes a limited number of users. Having a relatively small number of users provide ratings for content items causes many online systems to present different content items to different users of the group during different time intervals to obtain ratings for content items from various users of the group. However, many online systems also maintain one or more diversity rules that limit a number of times a content item may be presented to a user during a time interval. Enforcing these diversity rules may prevent a user of the group from being presented with a content item selected for presentation to the user that was previously presented to the same user of the group within a time interval specified by a diversity rule. This enforcement of diversity rules limiting presentation of content items may influence ratings provided by users of the group for various presented content items, which may impair training of a model for subsequent selection of content items to users that limits user interaction with the subsequently selected content items.